When it comes to building a strong core, the Swiss ball is anything but neutral, forcing you to recruit stabilising muscles in your midsection to counteract its natural wobble. Back in 2007, researchers at the University of Waterloo, Canada, found that adding a Swiss ball to a set of ab curls doubled the electromyography (EMG) electrical activity in the abs and oblique muscles. But what other exercises with a Swiss twist work these muscles well? Here’s the latest research.
The study: Scientists at California State University in the US looked at eight Swiss ball exercises: the roll-out, pike, knee-up, skier, hip extension right, hip extension left, decline push-up and sitting march. Hooked up to an EMG machine to record electrical activity in their muscles, 18 men and women each did five reps of each exercise. Traditional ab crunches and sit-ups acted as a point of comparison. Results were expressed in terms of maximum voluntary isometric contractions (MVICs).
The results: All the Swiss ball exercises resulted in higher EMG activity compared with traditional floor-based moves. But, says lead author Rafael F Escamilla, the roll-out and pike exercises were the most effective. Work them into your routine twice a week on rest days; try two or three sets of five to 10 reps, with 30 seconds’ rest in between.
The best abs exercise, the roll-out provides an upper rectus abdominis figure of 63 per cent MVIC, where the rest of the moves managed between seven and 53 per cent. For the lower rectus abdominis, the roll-out clocks 53 per cent, compared with a general range of seven to 44 per cent.
How to do it:
Start on your knees with forearms resting on the ball. Slowly roll forward, straightening your arms.
When you’re as far out as you can go without letting your back collapse, use your abs to pull yourself back in.
This move is good for the oblique muscles, which run down the side of the torso: it clocked 84 per cent MVIC for the external oblique and 56 per cent for the internal. That compares with a general range of 14-73% and 16-47% respectively.
How to do it:
Starting in the press-up position, place your feet behind you on the Swiss ball.
Keeping your legs straight, hinge at the hips and roll the ball forward with your feet.
Hold for three seconds, slowly roll back until your belly is parallel with the floor.